/**
***********************************************************************
*
* Copyright 2011 Stefan Wöhle
*
* This file is part of PixelMath
*
* PixelMath is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* PixelMath is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with PixelMath. If not, see <http://www.gnu.org/licenses/>.
*
***********************************************************************
*/

#ifndef FORMULA_H
#define FORMULA_H

#include <QObject>
#include <QImage>

/*********************************************************
 *
 *  Formula
 *
 *  This is the baseclass for all formula elements. It
 *  defines the common methos (value() and label()) and
 *  the global variable sourceImage which is mandatory
 *  for the concept of manipulating images.
 *
 **********************************************************/

class Formula : public QObject
{
    Q_OBJECT
protected:
    static QImage sourceImage;

public:
    static void setSourceImage(const QImage& src);
    explicit Formula(QObject* parent) : QObject(parent){}
    virtual double value(int x, int y) = 0; // throws FormulaException
    virtual QString label() = 0;

protected:
    void checkPreconditions(int x, int y); // throws FormulaException
};

#endif // FORMULA_H
